<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>copySign</title>
</head>

<body>
    <div>打开浏览器控制台查看结果</div>
    <script>
        const copySign = (x, y) => (Math.sign(x) === Math.sign(y) ? x : -x);
        console.log(copySign(2, 3)); // 2
        console.log(copySign(2, -3)); // -2
        console.log(copySign(-2, 3)); // 2
        console.log(copySign(-2, -3)); // -2
    </script>
</body>

</html>